Mapping functionality is added in between a Wireless Village (WV) server and a Presence, Messaging and Group (PMG) server of a 3GPP IP (Internet Protocol) Multimedia Subsystem (IMS) to permit interoperability between WV and IMS clients for instant messaging and presence services for operators who have deployed both IMS and WV. Due to the possibility that an operator may have deployed WV but not IMS and due to the use of a Client-to-Server Protocol (CSP) between WV clients and WV servers and the use of a Server-to-Server Protocol (SSP) between WV servers, the mapping functionality is structured to permit an IMS device to register into WV system via an IMS/WV Relay that performs an SIP/CSP conversion to emulate a WV device login but to then use the SSP to maintain a session or to deliver a message or presence information. Likewise, a WV device can register directly into IMS for operators not deploying WV using the mapping functionality of the present invention, e.g., in an IMS/WV Relay.